Internal combustion engines, including diesel engines, gasoline engines, gaseous fuel-powered engines, and other engines known in the art, exhaust a complex mixture of air pollutants. These air pollutants are composed of gaseous compounds such as, for example, oxides of nitrogen (NOx). Due to harmful effects of these pollutants, exhaust emission standards have become more stringent, and the amount of NOx emitted from an engine may be regulated. In order to regulate the amount of NOx and other gas emissions, exhaust systems rely on gas sensors. Some uses of these gas sensors require accurate information about the location of the gas sensors relative to the engine.
Sometimes the precise location of a gas sensor is not known, and instead, is based on an assumption or an estimate. For example, the manufacturer of the engine or the exhaust system may not be the installer of the system, and there is no guarantee that specifications for the placement of the gas sensor have been met during installation. In some situations, such as when the gas sensor is not where the manufacturer expects it to be, signals from the sensor cannot be relied upon for properly operating the exhaust system and/or detecting the concentration of gaseous compounds in the exhaust system.
Improperly or poorly positioned sensors can often be mischaracterized as being faulty, and engine manufacturers often utilize systems configured to detect faulty sensors. For example, one system configured to detect a faulty NOx sensor is described in U.S. Pat. No. 6,843,240 B1 (the '240 patent) issued to Hahn et al. on Jan. 18, 2005. The '240 patent discloses an exhaust system that monitors the function of a NOx sensor arranged in an exhaust duct. For example, the system compares an accumulative measure of the actual mass absorbed by a NOx storage catalytic converter with a target mass calculated based on a model for the NOx storage catalytic converter. The ratio of the actual mass to the target mass is then compared to predetermined limits to determine whether the NOx sensor is functioning. The '240 patent also discloses an alternative method of comparing a measured regeneration time of the NOx storage catalytic converter with a target regeneration time calculated based on a model for the NOx storage catalytic converter.
Although the system described in the '240 patent may be capable of determining the functionality of a NOx sensor, the system is not configured to detect whether a properly operating gas sensor has been installed incorrectly or in the wrong location.
The system of the present disclosure solves one or more of the problems set forth above and/or other problems.